Corrected entry: The scene where Paul Doyle has one of his big toes shot off while he is underwater is not possible because, as has been demonstrated by the Mythbusters, bullets completely shatter when they are fired into deep water.
Phaneron
11th Jun 2013
Correction: The mythbusters episode in question demonstrated that bullets fired at high velocity did come apart upon impacting the water surface. Bullets fired at low muzzle velocity not only broke the water surface, but penetrated the ballistics gel.